This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

NEW YORK — The New York City Health Department has issued summonses to three people for flouting an emergency order to vaccinate their children for measles.

The violations announced Thursday were issued to parents of unvaccinated children who had been exposed to measles. The parents could face a $1,000 fine if a hearing officer upholds the summons.

City officials announced an emergency vaccination order for four ZIP codes in Brooklyn last week, 11205, 11206, 11211 and 11249, in an effort to stem a measles outbreak that has sickened 329 people since October. A lawsuit challenging the order was dismissed by a state judge on Thursday.

Also on Thursday, the city health department closed four schools for failing to turn over vaccination and attendance records. A preschool that was closed earlier this week reopened under health department monitoring.

“Because of measles’ long incubation period, we know this outbreak will get worse before it gets better. However, we can turn the tide by people getting vaccinated, especially before Passover when families and communities will gather. We urge everyone to protect their children and their fellow New Yorkers by getting vaccinated immediately,” said Health Commissioner Dr. Oxiris Barbot.

Most cases have been reported from Williamsburg and Borough Park, Brooklyn. Five cases, including the initial case of measles, were acquired on a visit to Israel, where a large outbreak of the disease is occurring, according to the health department.

Measles is a highly contagious disease that is transmitted by airborne particles, droplets and direct contact with respiratory secretions of an infected person.

Symptoms, including fever, cough, runny nose and watery eyes, usually appear 10 to 12 days after exposure.

Measles can be prevented through vaccinations. New Yorkers are advised to call 311 to access a list of facilities that provide the MMR vaccine at little to no cost.